Okay I have always felt that my middle finger was the equivalent to my second toe and in my Osteology class (im in college) my professor was explaining the muscles of the fingers and toes:
So, you have your palmar interosseous muscles, which ADDUCT the fingers (moving toward the median plane), which on the hand would be your middle finger. You also have dorsal interosseous muscles, which ABDUCT the fingers, which means to move away from the median plane. Since your middle finger is literally on that plane, it does not have any palmar interosseous muscles (since it can't move towards the plane)- instead, it has two dorsal interosseous muscles, one for moving left and one for moving right.
In the foot, there is a similar system, but the median plane is NOT the third digit, it is the second. So, the second digit of the toes has two dorsal interosseous muscles, much like the third digit of the hand. This may be why we feel like they are analogous digits even though they are not the same number.
As for why your big toe feels like your pointer, I'm not exactly sure, but the only explanation I can think of is this:
Our primate ancestors had a divergent hallux (big toe) for grasping items, much like our thumbs. However, as our lineage shifted towards bipedalism, the big toe was needed to support weight and had less utility as a grasper. This loss of mobility in the big toes may be why it doesn't feel similar to the thumb: because functionally, it's not similar at all.
Hope this helps! You can thank the Evolutionary Anthropology department at Duke for this answer, hahaha.
My big toe feels like my pointer toe & 2nd toe feels like middle?
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Okay I have always felt that my middle finger was the equivalent to my second toe and in my Osteology class (im in college) my professor was explaining the muscles of the fingers and toes:
So, you have your palmar interosseous muscles, which ADDUCT the fingers (moving toward the median plane), which on the hand would be your middle finger. You also have dorsal interosseous muscles, which ABDUCT the fingers, which means to move away from the median plane. Since your middle finger is literally on that plane, it does not have any palmar interosseous muscles (since it can't move towards the plane)- instead, it has two dorsal interosseous muscles, one for moving left and one for moving right.
In the foot, there is a similar system, but the median plane is NOT the third digit, it is the second. So, the second digit of the toes has two dorsal interosseous muscles, much like the third digit of the hand. This may be why we feel like they are analogous digits even though they are not the same number.
As for why your big toe feels like your pointer, I'm not exactly sure, but the only explanation I can think of is this:
Our primate ancestors had a divergent hallux (big toe) for grasping items, much like our thumbs. However, as our lineage shifted towards bipedalism, the big toe was needed to support weight and had less utility as a grasper. This loss of mobility in the big toes may be why it doesn't feel similar to the thumb: because functionally, it's not similar at all.
Hope this helps! You can thank the Evolutionary Anthropology department at Duke for this answer, hahaha.